(a) Field of the Invention
The present invention relates to an engine starting control method for a hybrid vehicle. More particularly, the present invention relates to an engine starting control method which may improve drivability in engine starting of a hybrid vehicle.
(b) Description of the Related Art
Generally, a hybrid vehicle includes a starting motor, a drive motor, an engine, at least one planetary gear set, and a plurality of friction elements. In addition a hybrid vehicle may realize a plurality of shift modes according to connection states of the planetary gear set and friction elements. The starting motor may be defined as a motor which rotates a crankshaft to start the engine, and the drive motor may be defined as a motor which drives the vehicle. The starting motor and the drive motor are supplied electrical energy from a battery, and a drive shaft is rotated according to selective operations of the drive motor and the engine.
In the hybrid vehicle provided with a powertrain like the one described above without a power transmission device such as a clutch, if an engine and a drive shaft are not be separated appropriate through disengagement of a power transmission device, vibrations due to engine friction and starting motor torque may be transmitted to a drive shaft when the engine is stopped. Also, when torque of a starting motor is excessively higher than engine friction produced when an engine is started, an inertia torque of the starting motor may be transmitted to a drive shaft and thus vibrations may occur.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.